Next, using your scissors cut one of the index cards in
half. You will use each half of the index card to make a slit in the end
of the shoe box.
||Place the two halves of the index card over one of the holes,
creating a vertical slit (about 3/16" wide). Tape these pieces in place
using masking or scotch tape.|
|Next, cut out one eyepiece of the rainbow glasses (or a piece
of diffraction grating) and place it over the opening on the shoe box. Lightly
tape the diffraction grating in place.